Biodegradation

, Volume 8, Issue 3, pp 159–165

Degradation of catechin by Bradyrhizobium japonicum

Authors

  • Waheeta Hopper
    • Centre for Advanced Studies in BotanyUniversity of Madras
  • A. Mahadevan
    • Centre for Advanced Studies in BotanyUniversity of Madras
Article

DOI: 10.1023/A:1008254812074

Cite this article as:
Hopper, W. & Mahadevan, A. Biodegradation (1997) 8: 159. doi:10.1023/A:1008254812074

Abstract

Rhizobia utilize phenolic substances as sole carbonsource. Bradyrhizobium japonicum utilizescatechin, a unit of condensed tannin as carbonsource. To establish the degradative pathway ofcatechin, the products of catechin degradation wereisolated by paper chromatography and TLC andidentified by HPLC, UV, IR and NMR spectra. B.japonicum cleaves catechin through catechinoxygenase. Phloroglucinolcarboxylic acid andprotocatechuic acid were identified as the initialproducts of degradation. Phloroglucinolcarboxylicacid is further decarboxylated to phloroglucinolwhich is dehydroxylated to resorcinol. Resorcinolis hydroxylated to hydroxyquinol. Protocatechuicacid and hydroxyquinol undergo intradiol cleavagethrough protocatechuate 3,4-dioxygenase andhydroxyquinol 1,2-dioxygenase to formβ-carboxy cis, cis-muconic acidand maleylacetate respectively. The enzymes ofcatechin degradative pathway are inducible. Estimation of all the enzymes involved in thecatabolism of catechin reveals the existence of acatechin degradative pathway in B. japonicum.

Bradyrhizobium japonicumcondensed tanninscatechin degradation

Copyright information

© Kluwer Academic Publishers 1997